Обсуждение: Re: [Pljava-dev] stack depth limit exceeded - patch possible?
On Sat, 12 Apr 2008, Alexander W�hrer wrote: > I'm working on Windows XP SP2 (stack limit 3500 kb) and deployed > successfully my application (doing some external Web service calling) > inside PostGre 8.3.0. > > Unfortunatelly, the application needs at least 3 Threads and will run > for quite some time. > > I found this comment > > http://pgfoundry.org/pipermail/pljava-dev/2005/000491.html > > by Thomas Hallgren where he mentioned that PostGre only defines > one stack and therefor pl/java has no way of telling PostGre > about multiple thread stack pointers. > > My question is now if there is a patched version available of PostGre > 8.3.0 having this stack_depth check disabled? This was fixed in postgresql/pljava shortly after the referenced discussion. As requested, postgresql 8.1+ allows modification of stack_base_ptr so pljava can set it as desired. Kris Jurka
Dear Kris, am I understanding this correctly that pl/java sets it for the main Java thread, so other threads spawned by this main thread and using postgres SPI functionality will run into stack_depth_problems? I have read only access in this application, so maybe my envisioned patched version (check_stack_depth doing nothing) will work for my proof of concept tests. Can you suggest another workaround? Regards, Alexander Wöhrer > > > On Sat, 12 Apr 2008, Alexander Wöhrer wrote: > >> I'm working on Windows XP SP2 (stack limit 3500 kb) and deployed >> successfully my application (doing some external Web service calling) >> inside PostGre 8.3.0. >> >> Unfortunatelly, the application needs at least 3 Threads and will run >> for quite some time. >> >> I found this comment >> >> http://pgfoundry.org/pipermail/pljava-dev/2005/000491.html >> >> by Thomas Hallgren where he mentioned that PostGre only defines >> one stack and therefor pl/java has no way of telling PostGre >> about multiple thread stack pointers. >> >> My question is now if there is a patched version available of PostGre >> 8.3.0 having this stack_depth check disabled? > > This was fixed in postgresql/pljava shortly after the referenced > discussion. As requested, postgresql 8.1+ allows modification of > stack_base_ptr so pljava can set it as desired. > > Kris Jurka
On Mon, 14 Apr 2008, Alexander Wöhrer wrote: > am I understanding this correctly that pl/java sets it for the main Java > thread, so other threads spawned by this main thread and using postgres > SPI functionality will run into stack_depth_problems? pljava sets the stack_base_ptr for each thread just before it calls into the backend using SPI and resets it when that thread finishes using SPI. Only one thread can access the backend at a time, so multi-threaded pljava code is safe and this mangling of the stack_base_ptr keeps the backend happy. > Can you suggest another workaround? > Are you having any actual problems or is this all theoretical? I don't believe you should be having any issues, but if you're having a real problem, please post a self-contained test case so we can look into it. Kris Jurka